Modular plastic links for conveyors are typically formed of polyethylene, polypropylene or acetal, which are hard, wear resistant plastics having a low coefficient of friction ideal for pivoting the links and frictional contact with wear strip surfaces. These plastics also provide a high tensile strength along the belt for conveying heavy loads and ideal chemical and biological inactivity for use of the belts in sanitary and chemical environments. However, the low friction characteristics of the plastics do not form an ideal belt-to-load surface for carrying loads up and down inclines.
In the prior art, fabric and rubber-like belts have been used extensively to increase the friction of the carrying surface of the belts. However, these belts have certain shortcomings. Because significant friction between a fabric belt and its driving drum is required to effectively drive the belt, fabric belts are maintained in high tension, even while not operating. The high tension stretches the belt and strains the conveyor frame and tensioner. Another shortcoming with fabric belts is that they are not positively tracked, making them susceptible to edge damage as the untracked belt wanders from side to side. Repair is another problem with fabric belts. Removing worn sections, inserting splices, determining the correct length, and reinstalling and retensioning the repaired belt can be difficult. Furthermore, the roller carryways used with fabric belts are noisy.
It is therefore a primary object of this invention to resolve these problems by manufacture of high friction link belt modules and to provide improved high friction conveyor belts and conveyor systems.